Sold over here as the SMART Super Flash (in its non turbo incarnation) SMART produce a great value rear flashing light for commuters.

Very bright, with a default ON/OFF flashing pattern, and a price around ??13, I love these little lights.

The idea of a TURBO version is both alluring and frightening – much more powerful and the lights will probably begin to melt seatstays. Still, read what Bike Commuters thinks of them at the link above.